There are many who will readily agree with Mitchell's assertion that "the most interesting new directions (for computer-aided design) are suggested by the growing convergence of computation and telecommunication. This allows us to treat designing not just as a technical process... but also as a social process." [Mitchell 1995]. The assumption is that design was a social process until users of computer-aided design systems were distracted into treating it as a merely technical process. Most readers will assume that this convergence must and will lead to increased communication between design participants, that better social interaction leads to be better design. The unspoken assumption appears to be that putting the participants into an environment with maximal communication channels will result in design collaboration. The tools provided, therefore, must permit the best communication and the best social interaction. We see a danger here, a pattern being repeated which may lead us into less than useful activities. As with several (popular) architectural design or modelling systems already available, however, computer system implementations all too often are poor imitations manual systems. For example, few in the field will argue with the statement that the storage of data in layers in a computer-aided drafting system is an dispensable approach. Layers derive from manual overlay drafting technology [Stitt 1984] which was regarded as an advanced (manual) production concept at the time many software engineers were specifying CAD software designs. Early implementations of CAD systems (such as RUCAPS, GDS, Computervision) avoided such data organisation, the software engineers recognising that object-based structures are more flexible, permitting greater control of data editing and display. Layer-based systems, however, are easier to implement in software, more familiar to the user and hence easier to explain, initially easier to use but more limiting for an experienced and thoughtful user, leading in the end to a lesser quality in resultant drawings and significant problems in output control (see Richens [1990], pp. 31-40 for a detailed analysis of such features and constraints). Here then we see the design for architectural software faithfully but inappropriately following manual methods. So too is there a danger of assuming that the best social interaction is that done face-to-face, therefore all collaborative design communications environments must mimic face-to-face.